Automatic pan-tilt-zoom adjustment to improve vital sign acquisition

ABSTRACT

Techniques disclosed herein relate to automatic pan-tilt-zoom adjustment to improve vital sign acquisition. In various embodiments, a vital sign acquisition camera ( 176 ) operable to pan, tilt, and zoom (“PTZ”) may capture ( 402 ) an image of a patient ( 100 ). The image may be analyzed ( 404 ) to detect a depicted position of the patient within an image coordinate space of the image. A desired position of the patient within the image coordinate space of the image may determined ( 406 ), and a difference in the image coordinate space between the depicted position and the desired position may be calculated ( 408 ). The difference may then be mapped ( 410 ) from the image coordinate space to a PTZ space. One or more PTZ parameters of the vital sign acquisition camera may be altered ( 412 ) based on the mapping. After altering the one or more PTZ parameters, the vital sign acquisition camera may acquire ( 414 ) one or more vital signs from the patient.

TECHNICAL FIELD

The present disclosure is directed generally to health care. Moreparticularly, but not exclusively, various methods and apparatusdisclosed herein relate to unobtrusively acquiring vital signs frompatients.

BACKGROUND

There are a variety of scenarios in which it would be desirable tounobtrusively (e.g., without making contact) acquire vital signs frompatients. For example, when patients visit the emergency department of ahospital, they typically are triaged to determine various informationabout the patients, such as their names, ages, heights, weights, vitalsigns, reasons for visiting, and other similar information. Oncetriaged, the patients are sent to an area such as a waiting room to waitfor hospital resources such as physicians to become available to examineand/or treat the patients. Wait times for the patients may besignificant depending on availability of hospital resources, and duringthese waits their conditions may deteriorate. Requiring busy hospitalpersonnel to manually monitoring these patients' conditions fordeterioration is often prohibitive. Similarly, the conditions ofoutpatients at home may deteriorate over time, and yet deployinghospital personnel to the outpatients' homes to monitor the outpatientsmay require inordinate resources.

SUMMARY

The present disclosure is directed to methods, systems, and apparatusfor monitoring changes in conditions of patients using so-called “vitalsign acquisition cameras” that are configured to unobtrusively acquire avariety of vital signs from patients without expending significantresources. These vital signs may include but are not limited totemperature, pulse rate, peripheral capillary oxygen saturation(“SpO₂”), respiration rate, posture, and so forth. In order for vitalsign acquisition cameras to accurately and efficiently obtain vitalsigns from patients, it may be preferable that the patients be locatedat a particular position within a frame of the vital sign acquisitioncamera. Accordingly, techniques are described herein for automaticallyadjusting various parameters of vital sign acquisition cameras to ensurethat patients are properly positioned within the frame. For example, insome embodiments, a vital sign acquisition camera may obtain the mostaccurate vital signs when it is properly aimed and/or focused on apatient's head and/or torso.

Generally, in one aspect, a method may include: capturing, by a vitalsign acquisition camera, an image of a patient, wherein the vital signacquisition camera is operable to pan, tilt, and zoom (“PTZ”); analyzingthe image to detect a depicted position of the patient within an imagecoordinate space of the image; determining a desired position of thepatient within the image coordinate space of the image; calculating adifference in the image coordinate space between the depicted positionand the desired position; mapping the difference from the imagecoordinate space to a PTZ space; altering one or more PTZ parameters ofthe vital sign acquisition camera based on the mapping; and afteraltering the one or more PTZ parameters, acquiring, by the vital signacquisition camera, one or more vital signs from the patient.

In various embodiments, the analyzing may include detecting one or moresizes of one or more depicted portions of the patient within the imagecoordinate space of the image. In various embodiments, the method mayfurther include determining one or more desired sizes of the one or moredepicted portions of the patient within the image coordinate space ofthe image. In various embodiments, the difference in the imagecoordinate space may include one or more scale differences between thedetected one or more sizes of the one or more depicted portions of thepatient and the one or more desired sizes. In various embodiments, themapping may be based on prior calibration of the vital sign acquisitioncamera. In various embodiments, the prior calibration may includeestimating a focal length at each of a plurality of zoom levels of thevital sign acquisition camera.

Other implementations may include a non-transitory computer readablestorage medium storing instructions executable by a processor to performa method such as one or more of the methods described above. Yet anotherimplementation may include a control system including memory and one ormore processors operable to execute instructions, stored in the memory,to implement one or more modules or engines that, alone or collectively,perform a method such as one or more of the methods described above.

It should be appreciated that all combinations of the foregoing conceptsand additional concepts discussed in greater detail below (provided suchconcepts are not mutually inconsistent) are contemplated as being partof the subject matter disclosed herein. In particular, all combinationsof claimed subject matter appearing at the end of this disclosure arecontemplated as being part of the subject matter disclosed herein. Itshould also be appreciated that terminology explicitly employed hereinthat also may appear in any disclosure incorporated by reference shouldbe accorded a meaning most consistent with the particular conceptsdisclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. Also, the drawings are notnecessarily to scale, emphasis instead generally being placed uponillustrating the principles of the disclosure.

FIG. 1 schematically illustrates a scenario in which selected aspects ofthe present disclosure may be practiced, in accordance with variousembodiments.

FIG. 2 illustrates one example of how a vital sign acquisition cameramay be calibrated to generate a mapping between image coordinate spaceand pan-tilt-zoom space, in accordance with various embodiments.

FIG. 3 depicts an example of a desired patient position within a frameof a vital sign acquisition camera, in accordance with variousembodiments.

FIG. 4 depicts an example method for practicing various aspects of thepresent disclosure, in accordance with various embodiments.

FIG. 5 depicts components of an example computer system.

FIGS. 6 and 7 schematically depict non-limiting examples of componentsof two example vital sign acquisition cameras, in accordance withvarious embodiments.

DETAILED DESCRIPTION

There are a variety of scenarios in which it would be desirable tounobtrusively (e.g., without making contact) acquire vital signs frompatients. For example, when patients visit the emergency department of ahospital, they typically are registered and triaged to determine variousinformation about the patients, such as their names, ages, heights,weights, vital signs, reasons for visiting, and other similarinformation. At triage, their urgency to see a physician and an estimateof resources required for diagnosis and treatment are established. Onceregistered and triaged, the patients are sent to an area such as awaiting room to wait for hospital resources such as physicians to becomeavailable to examine and/or treat the patients. Wait times for thepatients may be significant depending on availability of hospitalresources, and during these waits their conditions may deteriorate.Requiring busy hospital personnel to manually monitor these patients'conditions for deterioration would be prohibitive. Similarly, theconditions of outpatients at home may deteriorate over time, and yetdeploying hospital personnel to the outpatients' homes to monitor theoutpatients may require inordinate resources.

FIG. 1 schematically illustrates an example of how techniques describedherein may be employed, in accordance with various embodiments. Apatient 100 is seated in an area in which patient 100 is to beunobtrusively monitored by one or more vital sign acquisition cameras176. In various embodiments, vital sign acquisition camera 176 may be aso-called “pan-tilt-zoom” (“PTZ”) camera that is adjustable in theso-called “PTZ space” to point at different locations (e.g., byadjusting pan and tilt parameters) and to capture images at various zoomlevels (e.g., by adjusting a zoom parameter). In various embodiments,vital sign acquisition camera 176 may be equipped to perform so-called“contactless methods” to acquire vital signs and other physiologicalinformation from patient 100. Non-limiting examples of such cameras aredescribed in United States Patent Application Publication Nos.20140192177A1, 20140139656A1, 20140148663A1, 20140253709A1,20140235976A1, and 20140275880A1, which are incorporated herein byreference for all purposes. FIGS. 6 and 7 schematically depict twonon-limiting configurations of vital sign acquisition cameras that maybe employed in various embodiments of the present disclosure.

In FIG. 1, vital sign acquisition camera 176 is initially configured inthe PTZ space to capture patient 100 in the angle c. It can be seen fromthe corresponding frame at bottom left that when so-adjusted, patient100 is positioned off-center within the frame c (to the right and up).Moreover, patient 100 is relatively small within the frame c. In otherwords, patient 100 is sub-optimally framed. In such a PTZ configuration,vital sign acquisition camera 176 may not be able to accurately and/orefficiently capture one or more vital signs. For example, a torso ofpatient 100 may be too small within the frame to accurately capturerespiration rate.

Accordingly, in various embodiments, vital sign acquisition camera 176may be configured with selected aspects of the present disclosure toautomatically reconfigure itself (or be reconfigured by anothercomputing device, not depicted) in order to capture patient 100 withinits frame in a more optimal manner. In particular, one or more PTZparameters of vital sign acquisition camera 176 may be automaticallyadjusted based on a detected position of patient 100 within its frame tomore optimally capture patient 100 for purposes of acquiring one or morevital signs.

In FIG. 1, one or more PTZ parameters of vital sign acquisition camera176 may be automatically adjusted so that patient 100 is captured in theangle β, for which a corresponding frame β is depicted at bottom right.For example, the detected position of patient 100 within the frame α(i.e., within so-called “image coordinate space” of the frame, i.e.,Cartesian space) may be compared to a desired position of patient 100within the frame to determine a difference in scale and/or displacementof patient 100 between the detected and desired positions. Thisdifference in image coordinate space may then be mapped to the PTZ spaceof vital sign acquisition camera 176. One or more PTZ parameters ofvital sign acquisition camera 176 may be adjusted based on the mapping,and vital sign acquisition camera 176 may then be operated to acquireone or more vital signs from the patient. It can be seen in frame/thatpatient 100 is now more or less centered within the frame and occupies alarger portion of the frame. Consequently, vital sign acquisition camera176 is able to unobtrusively capture vital sign(s) from patient 100 moreaccurately.

The mapping between image coordinate space and PTZ space may bedetermined in various ways, and may be specific to the particular vitalsign acquisition camera 176 being used. Accordingly, in variousembodiments, vital sign acquisition camera 176 may be calibrated (e.g.,offline) to establish the mapping from image coordinate space to PTZspace. In some embodiments, calibration may include implementation oftechniques such as those described in “PTZ Camera Modeling and PanoramicView Generation via Focal Plane Mapping,” by Karthik Sankaranarayanananand James W. Davis, Asian Conference on Computer Vision, November 2010,which is incorporated herein by reference in its entirety for allpurposes. That paper describes how the mapping may rely on the camera'sfocal length f, which differs at each optical zoom level Z. In someembodiments, a test subject may be positioned at a distance from vitalsign acquisition camera 176. An optical zoom setting of vital signacquisition camera 176 may be adjusted from low to high, e.g., from therange of zero to twenty in increments of one. At each optical zoomsetting, a focal length f may be calculated. The focal length f may becalculated at each optical zoom setting in various ways.

FIG. 2 demonstrates one non-limiting technique for calculating focallength f at each optical zoom setting z. For each optical zoom setting za pan setting (or parameter) θ of vital sign acquisition camera 176 maybe varied among a plurality N of arbitrarily selected values, {θ₁, θ₂,θ₃, . . . , θ_(N)}. At each pan setting θ_(i), a reference point P_(i)of the test subject, such as a center of the test subject's face, may bedetected in image coordinate space (e.g., using facial detectionprocessing on an image captured using vital sign acquisition camera176). In this manner, a plurality N of reference points of the testsubject, {P₁, P₂, P₃, . . . , P_(N),}, may be generated. Each referencepoint P may include an x coordinate and a y coordinate in imagecoordinate space.

Then, for each pair of arbitrarily select pan settings, {θ_(i), θ_(j)},a focal length f can be calculated using equations such as thefollowing:

$\begin{matrix}{{\delta \; \theta} = {\tan^{- 1}\left( \frac{x}{{y\; \sin \; \varphi} + {f\; \cos \; \varphi}} \right)}} & (1) \\{{\delta \; \varphi} = {\tan^{- 1}\left( \frac{\frac{y + a}{\cos \left( {\tan^{- 1}\left( {\frac{a}{b}\frac{x}{y + a}} \right)} \right)} - a}{f} \right)}} & (2) \\{{{\delta \; \theta_{i}} + {{\delta \; \theta_{j}}}} = {\theta_{j} - \theta_{i}}} & (3)\end{matrix}$

δθ represents a change in pan θ_(i) between θ_(j) and δϕ and dorepresents a change in tilt ϕ (which may be 0 if tilt is not altered).The parameters a and b may be camera-related parameters that can bedetermined using equations such as the following:

a=f/tan−ϕ

b=a/sin ϕ

Equation (1) may be plugged into equation (3). θ_(i), θ_(j), are known,which means the only unknown in the resulting equation is the focallength f. Accordingly, the resulting equation may be solved for f. Then,an average f_(avg) of all calculated focal lengths f from all theN(N−1)/2 selected pan pairs at the current optical zoom level z may becalculated, and that average f_(avg) may be used as the accepted focallength f for the current optical zoom level z of vital sign acquisitioncamera 176. Then, vital sign acquisition camera 176 may be adjusted tothe next optical zoom setting z and the process may be repeated.

Other similar techniques may be employed to calibrate vital signacquisition camera 176 to establish the mapping between image coordinatespace and PTZ space. For example, some cameras may include a pluralityof discrete zoom settings s, e.g., 1-20, that a user may select toachieve a desired zoom level. Each discrete zoom setting s of the cameramay be associated with a particular optical zoom level z that isimplemented when the user selects the discrete zoom setting s. For atleast some cameras, the relationship between discrete zoom levels s ofthe camera and corresponding implemented optical zoom levels z may beavailable, e.g., as part of a user manual. When optical zoom levels zare available in this way, a focal length f at least optical zoom levelmay be directly estimated, e.g., using an equation such as the following

f=z*C

wherein C is a constant greater than zero that may estimated from theconfiguration of the PTZ camera being used and which may becamera-dependent.

Once the mapping between image coordinate space and PTZ is established,e.g., using one of the techniques set forth above, vital signacquisition camera 176 may be reconfigured (i.e. its PTZ parameters maybe adjusted) automatically whenever a patient-to-be-monitored iscaptured within its frame, so that the patient can be properlypositioned within the frame for improved vital sign acquisition. Asnoted above, in some embodiments, a depicted position of a patientwithin a frame may be compared with a “desired” position of the patientwithin the frame. The desired position of the patient in the frame maybe determined in various ways. In some embodiments, the desired positionmay be an empirically-determined “ideal” position that may include oneor more defined points of the patient's face and/or torso being atvarious locations and/or having various scales/sizes in the imagecoordinate space. For example, and as is depicted in FIG. 3, in someembodiments, the following values may be used for desired face positionas an offset from the top of the frame, d_(j), and desired face width,w_(f):

d _(f)=0.1l _(f)

w _(f)=0.33w

z _(f) =w _(f) *z _(d) /w _(d)

l _(f) =z _(f) *l _(d) /z _(d)

wherein l_(f) equals the length of the patient's face top-to-bottom(e.g., in pixels), w is the width of the frame (e.g., in pixels), andw_(d), l_(d) and z_(d) are the detected face width, length and scale,respectively. However, this is just one example, and any other valuesmay be used instead.

Once the difference (e.g., displacement and/or change in scale) isdetermined between the detected position of patient 100 within the frameand the desired position, Equations (1)-(3) described above may be usedto determine the mapping to PTZ space. With this mapping, the PTZparameters of image acquisition camera may be adjusted, so that vitalsigns may be acquired from patient 100.

FIG. 4 depicts an example method 400 for automatically adjusting one ormore PTZ parameters of a vital sign acquisition camera (e.g., 100) sothat vital signs may be unobtrusively acquired from a patient. Forconvenience, some of the operations of method 400 are described withreference to a system that performs the operations. This system mayinclude various components of various computer systems, includinginternal logic (e.g., FPGA, ASIC, microprocessor) of vital signacquisition camera 176 itself. Moreover, while operations of method 400are shown in a particular order, this is not meant to be limiting. Oneor more operations may be reordered, omitted or added.

At block 402, the system may capture an initial image of apatient-to-be-monitored with a PTZ camera, such as the vital signacquisition camera 176 described above. For example, vital signacquisition camera 176 may scan an area such as a waiting room filledwith patients or an outpatient's home and capture an image when itdetects a patient within its frame. In some embodiments, vital signacquisition camera 176 may scan an area using a predeterminedtrajectory, such as a trajectory that passes one or more rows of chairsin which waiting patients may be sitting, or a trajectory that iteratesthrough locations in an outpatient's home that are known to be inhabitedfrequently by the outpatient.

However the initial image of the patient is captured, at block 404, thesystem may analyze the image to detect a depicted position of thepatient within the coordinate space (e.g., x, y space) of the image. Thesystem may detect the patient's depicted position in various ways. Insome embodiments, the system may employ techniques such as edgedetection to detect outer edges of the patient within the image frame.In other embodiments, the system may perform face detection to detectthe patient's depicted face position within the image frame. Thedepicted position of the patient's face within the frame may include avariety of information, such as the patient's absolute position, sizesof one or more portions of the patient (e.g., head, neck, shoulders,etc.), relative positions of one or more portions of the patient, and soforth. Some of the spatial metrics that may be detected were describedabove with respect to FIG. 3.

At block 404, the system may determine a desired position of the patientwithin the coordinate space of the image. In some embodiments, a desiredposition of the patient may be preset manually to include one or moreconstants, e.g., such as d_(f) and l_(f) described above with respect toFIG. 3. In some embodiments, the desired position of the patient may bedetermined and/or dynamically adjusted based on a variety of factors,such as lighting within the room, clothing worn by the patient (whichmay affect how respiration rate may be detected from the patient'storso), a size of the patient, a health condition of the patient, and soforth.

Referring back to FIG. 4, however the desired position of the patientwithin the frame is determined, at block 408, a difference between thedetected position of patient determined at block 404 and the desiredposition determined at block 406 in image coordinate space may becalculated. In various embodiments, this difference may includetranslational components (e.g., translation along the x and y axes)and/or scaling components (e.g., the patient's head needs to be enlargedby a factor of δz.

At block 410, the system may map the difference in image coordinatespace calculated at block 408 to PTZ space of vital sign acquisitioncamera 176. As described above, this mapping may be based on thecalibration of vital sign acquisition camera 176 where a focal length fat each zoom level z was calculated. In some embodiments, equations suchas Equation (1)-(3) above may be used to map the difference in imagecoordinate space to PTZ space of vital sign acquisition camera 176. Invarious embodiments, the mapping may include a change in pan (δθ), achange in tilt (δϕ), and/or a change in zoom (δz).

At block 412, the system may alter one or more PTZ parameters of vitalsign acquisition camera 176 based on the mapping (e.g., δθ, δϕ, δz) ofblock 410. At block 414, the system may operate vital sign acquisitioncamera 176 to unobtrusively acquire one or more vital signs from thepatient. As noted above, these vital signs may include but are notlimited to temperature, pulse rate, peripheral capillary oxygensaturation (“SpO₂”), respiration rate, posture, and so forth.

FIG. 5 is a block diagram of an example computer system 510. Computersystem 510 typically includes at least one processor 514 whichcommunicates with a number of peripheral devices via bus subsystem 512.As used herein, the term “processor” will be understood to encompassvarious devices capable of performing the various functionalitiesattributed to the CDS system described herein such as, for example,microprocessors, FPGAs, ASICs, other similar devices, and combinationsthereof. These peripheral devices may include a data retention subsystem524, including, for example, a memory subsystem 525 and a file storagesubsystem 526, user interface output devices 520, user interface inputdevices 522, and a network interface subsystem 516. The input and outputdevices allow user interaction with computer system 510. Networkinterface subsystem 516 provides an interface to outside networks and iscoupled to corresponding interface devices in other computer systems.

User interface input devices 522 may include a keyboard, pointingdevices such as a mouse, trackball, touchpad, or graphics tablet, ascanner, a touchscreen incorporated into the display, audio inputdevices such as voice recognition systems, microphones, and/or othertypes of input devices. In general, use of the term “input device” isintended to include all possible types of devices and ways to inputinformation into computer system 510 or onto a communication network.

User interface output devices 520 may include a display subsystem, aprinter, a fax machine, or non-visual displays such as audio outputdevices. The display subsystem may include a cathode ray tube (CRT), aflat-panel device such as a liquid crystal display (LCD), a projectiondevice, or some other mechanism for creating a visible image. Thedisplay subsystem may also provide non-visual display such as via audiooutput devices. In general, use of the term “output device” is intendedto include all possible types of devices and ways to output informationfrom computer system 510 to the user or to another machine or computersystem.

Data retention system 524 stores programming and data constructs thatprovide the functionality of some or all of the modules describedherein. For example, the data retention system 524 may include the logicto perform selected aspects of method 400, and/or to implement one ormore components of vital sign acquisition camera 176 or a computingdevice that controls operation of vital sign acquisition camera 176.

These software modules are generally executed by processor 514 alone orin combination with other processors. Memory 525 used in the storagesubsystem can include a number of memories including a main randomaccess memory (RAM) 530 for storage of instructions and data duringprogram execution, a read only memory (ROM) 532 in which fixedinstructions are stored, and other types of memories such asinstruction/data caches (which may additionally or alternatively beintegral with at least one processor 514). A file storage subsystem 526can provide persistent storage for program and data files, and mayinclude a hard disk drive, a floppy disk drive along with associatedremovable media, a CD-ROM drive, an optical drive, or removable mediacartridges. The modules implementing the functionality of certainimplementations may be stored by file storage subsystem 526 in the dataretention system 524, or in other machines accessible by theprocessor(s) 514. As used herein, the term “non-transitorycomputer-readable medium” will be understood to encompass both volatilememory (e.g. DRAM and SRAM) and non-volatile memory (e.g. flash memory,magnetic storage, and optical storage) but to exclude transitorysignals.

Bus subsystem 512 provides a mechanism for letting the variouscomponents and subsystems of computer system 510 communicate with eachother as intended. Although bus subsystem 512 is shown schematically asa single bus, alternative implementations of the bus subsystem may usemultiple busses.

Computer system 510 can be of varying types including a workstation,server, computing cluster, blade server, server farm, or any other dataprocessing system or computing device. In some embodiments, computersystem 510 may be implemented within a cloud computing environment. Dueto the ever-changing nature of computers and networks, the descriptionof computer system 510 depicted in FIG. 4 is intended only as a specificexample for purposes of illustrating some implementations. Many otherconfigurations of computer system 510 are possible having more or fewercomponents than the computer system depicted in FIG. 5.

FIG. 6 shows a schematic diagram of a first embodiment of a vital signacquisition camera 676 that may be employed in various embodimentsdescribed herein. Electromagnetic radiation 682, in particular light inthe visible and infrared wavelength range, reflected from a living being684, such as a patient, is received and evaluated by said camera 676 togenerate a biometrical signal 698 of the living being 684. The camera676 may include a filter 686 for blocking incident visible light withinthe incident electromagnetic radiation 682 in a wavelength range up tosubstantially 550 nm, and/or up to approximately 600 nm, and/or up to650 nm. The filtered incident light 688 is then sensed by a color sensor690 that generates at least two different color signals 692 _(A), 692_(B), e.g. by use of two separate color detectors 693, 694 (or an arrayof such color detectors). A combination unit 695 generates at least onecombined color signal 696 by combining said color signals 692 _(A), 692_(B), e.g. by a linear combination. Finally, a processing unit 697 isprovided for processing said combined color signal 696 and extracting atleast one biometrical signal 698 of the living being 684. Thecombination unit 695 and the processing unit 697 may be realized in someembodiments by a common processor 699, e.g. as processing elements of aprocessor or implemented in software on a conventional processor.However, they may also be realized in a different manner, e.g. asdedicated hardware elements.

FIG. 7 schematically shows a second embodiment of a camera 776′ that maybe employed in various embodiments described herein. FIG. 7 shows thatoptionally an additional filter 786′ may be provided (in this and/orother embodiments), which filter 786′ is configured to block incidentlight in a wavelength range above at least 1100 nm, in particular aboveat least 1000 nm, before reaching the color sensor 790. While generallythose color sensors, e.g. imaging silicon sensors, show a sensitivitythat naturally decreases towards longer wavelengths, such an additionalfilter 786′ may ensure that signal contributions within the filteredincident light 788 above said upper threshold wavelength are blocked,i.e. signal contributions in which water absorption becomes dominant areblocked in the twice filtered incident light 788′.

Further, in this embodiment the color sensor 790 generates threedifferent color signals 792 _(A), 792 _(B), 792 _(C), e.g. by use of acolor filter array 793 having three different color filter areasprovided in front of a photo detector 795 (or, more generally, the imagesensor). Such a color sensor (e.g. including a color filter array havingonly two color filter areas) could also be used in the embodiment shownin FIG. 6. In some embodiments, the color sensor 790 may include a colorfilter array generating a red color signal 792 _(A), a green colorsignal 792 _(B) and a blue color signal 792 _(C) as conventionallyprovided by an RGB color sensor. From the three color signals 792 _(A),792 _(B), 792 _(C), the combination unit 795 generates two combinedcolor signals 796 _(A), 796 _(B) by making two different combinations,in particular linear combinations, of at least two of said three colorsignals 792 _(A), 792 _(B), 792 _(C). From these two combined colorsignals 796 _(A), 796 _(B) the processing unit then finally extracts thedesired biometrical signal 798 from the living being 784.

While several embodiments have been described and illustrated herein,those of ordinary skill in the art will readily envision a variety ofother means and/or structures for performing the function and/orobtaining the results and/or one or more of the advantages describedherein, and each of such variations and/or modifications is deemed to bewithin the scope of the embodiments described herein. More generally,those skilled in the art will readily appreciate that all parameters,dimensions, materials, and configurations described herein are meant tobe exemplary and that the actual parameters, dimensions, materials,and/or configurations will depend upon the specific application orapplications for which the teachings is/are used. Those skilled in theart will recognize, or be able to ascertain using no more than routineexperimentation, many equivalents to the specific embodiments describedherein. It is, therefore, to be understood that the foregoingembodiments are presented by way of example only and that, within thescope of the appended claims and equivalents thereto, embodiments may bepracticed otherwise than as specifically described and claimed.Inventive embodiments of the present disclosure are directed to eachindividual feature, system, article, material, kit, and/or methoddescribed herein. In addition, any combination of two or more suchfeatures, systems, articles, materials, kits, and/or methods, if suchfeatures, systems, articles, materials, kits, and/or methods are notmutually inconsistent, is included within the scope of the presentdisclosure.

All definitions, as defined and used herein, should be understood tocontrol over dictionary definitions, definitions in documentsincorporated by reference, and/or ordinary meanings of the definedterms.

The indefinite articles “a” and “an,” as used herein in thespecification and in the claims, unless clearly indicated to thecontrary, should be understood to mean “at least one.”

The phrase “and/or,” as used herein in the specification and in theclaims, should be understood to mean “either or both” of the elements soconjoined, i.e., elements that are conjunctively present in some casesand disjunctively present in other cases. Multiple elements listed with“and/or” should be construed in the same fashion, i.e., “one or more” ofthe elements so conjoined. Other elements may optionally be presentother than the elements specifically identified by the “and/or” clause,whether related or unrelated to those elements specifically identified.Thus, as a non-limiting example, a reference to “A and/or B”, when usedin conjunction with open-ended language such as “comprising” can refer,in one embodiment, to A only (optionally including elements other thanB); in another embodiment, to B only (optionally including elementsother than A); in yet another embodiment, to both A and B (optionallyincluding other elements); etc.

As used herein in the specification and in the claims, “or” should beunderstood to have the same meaning as “and/or” as defined above. Forexample, when separating items in a list, “or” or “and/or” shall beinterpreted as being inclusive, i.e., the inclusion of at least one, butalso including more than one, of a number or list of elements, and,optionally, additional unlisted items. Only terms clearly indicated tothe contrary, such as “only one of” or “exactly one of,” or, when usedin the claims, “consisting of,” will refer to the inclusion of exactlyone element of a number or list of elements. In general, the term “or”as used herein shall only be interpreted as indicating exclusivealternatives (i.e. “one or the other but not both”) when preceded byterms of exclusivity, such as “either,” “one of,” “only one of,” or“exactly one of.” “Consisting essentially of,” when used in the claims,shall have its ordinary meaning as used in the field of patent law.

As used herein in the specification and in the claims, the phrase “atleast one,” in reference to a list of one or more elements, should beunderstood to mean at least one element selected from any one or more ofthe elements in the list of elements, but not necessarily including atleast one of each and every element specifically listed within the listof elements and not excluding any combinations of elements in the listof elements. This definition also allows that elements may optionally bepresent other than the elements specifically identified within the listof elements to which the phrase “at least one” refers, whether relatedor unrelated to those elements specifically identified. Thus, as anon-limiting example, “at least one of A and B” (or, equivalently, “atleast one of A or B,” or, equivalently “at least one of A and/or B”) canrefer, in one embodiment, to at least one, optionally including morethan one, A, with no B present (and optionally including elements otherthan B); in another embodiment, to at least one, optionally includingmore than one, B, with no A present (and optionally including elementsother than A); in yet another embodiment, to at least one, optionallyincluding more than one, A, and at least one, optionally including morethan one, B (and optionally including other elements); etc.

It should also be understood that, unless clearly indicated to thecontrary, in any methods claimed herein that include more than one stepor act, the order of the steps or acts of the method is not necessarilylimited to the order in which the steps or acts of the method arerecited.

In the claims, as well as in the specification above, all transitionalphrases such as “comprising,” “including,” “carrying,” “having,”“containing,” “involving,” “holding,” “composed of,” and the like are tobe understood to be open-ended, i.e., to mean including but not limitedto. Only the transitional phrases “consisting of” and “consistingessentially of” shall be closed or semi-closed transitional phrases,respectively, as set forth in the United States Patent Office Manual ofPatent Examining Procedures, Section 2111.03. It should be understoodthat certain expressions and reference signs used in the claims pursuantto Rule 6.2(b) of the Patent Cooperation Treaty (“PCT”) do not limit thescope

1. A computer-implemented method, comprising: capturing, by a vital signacquisition camera, an image of a patient, wherein the vital signacquisition camera is operable to pan, tilt, and zoom (“PTZ”); analyzingthe image to detect a depicted position of the patient within an imagecoordinate space of the image; determining a desired position of thepatient within the image coordinate space of the image; calculating adifference in the image coordinate space between the depicted positionand the desired position; mapping the difference from the imagecoordinate space to a PTZ space; altering one or more PTZ parameters ofthe vital sign acquisition camera based on the mapping; and afteraltering the one or more PTZ parameters, acquiring, by the vital signacquisition camera, one or more vital signs from the patient.
 2. Thecomputer-implemented method of claim 1, wherein the analyzing includesdetecting one or more sizes of one or more depicted portions of thepatient within the image coordinate space of the image.
 3. Thecomputer-implemented method of claim 2, further comprising: determiningone or more desired sizes of the one or more depicted portions of thepatient within the image coordinate space of the image; wherein thedifference in the image coordinate space includes one or more scaledifferences between the detected one or more sizes of the one or moredepicted portions of the patient and the one or more desired sizes. 4.The computer-implemented method of claim 1, wherein the mapping is basedon prior calibration of the vital sign acquisition camera.
 5. Thecomputer-implemented method of claim 4, wherein the prior calibrationincludes estimating a focal length at each of a plurality of zoom levelsof the vital sign acquisition camera.
 6. A system comprising one or moreprocessors and memory operably coupled with the one or more processors,wherein the memory stores instructions that, in response to execution ofthe instructions by one or more processors, cause the one or moreprocessors to: capture, by a vital sign acquisition camera, an image ofa patient, wherein the vital sign acquisition camera is operable to pan,tilt, and zoom (“PTZ”); analyze the image to detect a depicted positionof the patient within an image coordinate space of the image; determinea desired position of the patient within the image coordinate space ofthe image; calculate a difference in the image coordinate space betweenthe depicted position and the desired position; map the difference fromthe image coordinate space to a PTZ space; alter one or more PTZparameters of the vital sign acquisition camera based on the mapping;and after altering the one or more PTZ parameters, acquire, by the vitalsign acquisition camera, one or more vital signs from the patient. 7.The system of claim 6, further comprising instructions to detect one ormore sizes of one or more depicted portions of the patient within theimage coordinate space of the image.
 8. The system of claim 7, furthercomprising instructions to: determine one or more desired sizes of theone or more depicted portions of the patient within the image coordinatespace of the image; wherein the difference in the image coordinate spaceincludes one or more scale differences between the detected one or moresizes of the one or more depicted portions of the patient and the one ormore desired sizes.
 9. The system of claim 6, wherein the mapping isbased on prior calibration of the vital sign acquisition camera.
 10. Thesystem of claim 9, wherein the prior calibration includes estimating afocal length at each of a plurality of zoom levels of the vital signacquisition camera.
 11. At least one non-transitory computer-readablemedium comprising instructions that, in response to execution of theinstructions by one or more processors, cause the one or more processorsto perform the following operations capturing, by a vital signacquisition camera, an image of a patient, wherein the vital signacquisition camera is operable to pan, tilt, and zoom (“PTZ”); analyzingthe image to detect a depicted position of the patient within an imagecoordinate space of the image; determining a desired position of thepatient within the image coordinate space of the image; calculating adifference in the image coordinate space between the depicted positionand the desired position; mapping the difference from the imagecoordinate space to a PTZ space; altering one or more PTZ parameters ofthe vital sign acquisition camera based on the mapping; and afteraltering the one or more PTZ parameters, acquiring, by the vital signacquisition camera, one or more vital signs from the patient.
 12. The atleast one non-transitory computer-readable medium of claim 11, whereinthe analyzing includes detecting one or more sizes of one or moredepicted portions of the patient within the image coordinate space ofthe image.
 13. The at least one non-transitory computer-readable mediumof claim 12, further comprising instructions that cause the one or moreprocessors to perform the following operations: determining one or moredesired sizes of the one or more depicted portions of the patient withinthe image coordinate space of the image; wherein the difference in theimage coordinate space includes one or more scale differences betweenthe detected one or more sizes of the one or more depicted portions ofthe patient and the one or more desired sizes.
 14. The at least onenon-transitory computer-readable medium of claim 11, wherein the mappingis based on prior calibration of the vital sign acquisition camera. 15.The at least one non-transitory computer-readable medium of claim 14,wherein the prior calibration includes estimating a focal length at eachof a plurality of zoom levels of the vital sign acquisition camera.